As used herein, the term “smoking article” includes smokable products such as cigarettes, cigars and cigarillos whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes and also heat-not-burn products.
Low ignition propensity (LIP) smoking articles generally comprise a specific low ignition propensity wrapper wrapped around a core of tobacco. When the smoking article is lit, the low ignition propensity wrapper restricts the access of external air to the burning tobacco core and, as such, may cause the smoking article to self-extinguish if it is not regularly drawn upon by the smoker.
ASTM E2187-04 and ASTM E2187-09 specify standardized tests which can be used to assess the ignition propensity properties of smoking articles. National regulation often requires that low ignition propensity smoking articles exhibit full length burn percentages of less than a particular threshold, for example 25%, when tested in accordance with ASTM E2187-04 or ASTM E2187-09.
The wrappers of commercially available low ignition propensity smoking articles generally comprise a base paper onto which bands of burn limiting additive material have been applied. The bands of additive material generally have a lower air permeability than the inherent air permeability of the base paper, and thus reduce the air permeability of the wrapper in the banded regions. This reduction in air permeability decreases the amount of air available to the burning tobacco and consequently can be used to reduce the ignition propensity of smoking articles in accordance with industry standards such as ASTM E2187-04 and ASTM E2187-09.
However, the production of LIP smoking articles with banded LIP wrappers of this type can be complex, costly and time inefficient. This is because, conventionally, a two stage wrapper manufacturing process is used in which an initial base paper production stage is followed by a separate additive material application stage. This presents difficulties in terms of manufacturing the wrapper “on-line” in a smoking article assembly unit. To avoid these difficulties, the banded wrapper is generally manufactured separately before being loaded into the smoking article assembly unit. The additive material itself is also expensive when compared to materials used in conventional smoking article wrappers.